With the help of classification society specification and MATLAB software, a program that can extract the acceleration of Floating Production Storage and Offloading (FPSO) pipeline at any position is developed, so as to better analyze the stress of main deck cooling water piping system of FPSO. The actual acceleration value at any position of the system and the acceleration value at the center of gravity of FPSO hull are respectively applied to the pipeline in the form of uniform load, and the stress change of the system under full load condition is analyzed with CAESAR Ⅱ software. The results show that, under full load condition of FPSO, the stress redundancy and stress deficiency occur with the results obtained by acceleration value of center of gravity compared with the actual acceleration value of FPSO itself. For example, the stress of Node 50 increases by 1.01%, while the stress of Node 2570 decreases by 0.19%.